Index: src/effects/gradients/SkMeshGradient.h |
diff --git a/src/effects/gradients/SkMeshGradient.h b/src/effects/gradients/SkMeshGradient.h |
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+/* |
+ * Copyright 2014 Google Inc. |
+ * |
+ * Use of this source code is governed by a BSD-style license that can be |
+ * found in the LICENSE file. |
+ */ |
+ |
+#ifndef SkMeshGradient_DEFINED |
+#define SkMeshGradient_DEFINED |
+ |
+#include "SkPatch.h" |
+#include "SkCanvas.h" |
+ |
+/** |
+ * Class that represents a Mesh Gradient. A mesh gradient is an array of coons patches, adjacent |
+ * patches share their corners and a color is specified at each one of them. The colors are |
+ * bilinearly interpolated across the patch. |
+ * |
+ * This implementation defines a bidimensional array of patches. There are 3 arrays to store the |
+ * control points of the patches to avoid storing repeated data since there are several points |
+ * shared between adjacent patches. |
+ * |
+ * The array fCornerPts stores the corner control points of the patches. |
+ * The array fHrzPts holds the intermidiate control points of the top and bottom curves of a patch. |
+ * The array fVrtPts holds the intermidiate control points of the left and right curves of a patch. |
+ * The array fCornerColors holds the corner colors in the same format as fCornerPts. |
+ * The array fExists holds bools to determine if there is an existing patch at a certain location of |
egdaniel
2014/08/07 17:58:55
Can remove the comments about fExists
dandov
2014/08/07 18:11:46
Done.
|
+ * the grid. |
+ * |
+ * fExists fCornerPts fHrzPts fVrtPts |
+ * ------- -------------- ------------------- -------------- |
+ * | 1 | 1 | | C0 | C1 | C2 | | H0 | H1 | H2 | H3 | | V0 | V1 | V2 | |
+ * ------- -------------- ------------------ --------------- |
+ * | 1 | 1 | | C3 | C4 | C5 | | H4 | H5 | H6 | H7 | | V4 | V5 | V6 | |
+ * ------- -------------- ------------------- -------------- |
+ * | C6 | C7 | C8 | | H8 | H9 | H10| H11| | V6 | V7 | V8 | |
+ * -------------- ------------------- -------------- |
+ * | V9 | V10| V11| |
+ * -------------- |
+ * |
+ * With the above configuration we would have a 2x2 grid of patches: |
+ * H0 H1 H2 H3 |
+ * / \/ \ |
+ * C0-------C1-------C2 |
+ * /| | |\ |
+ * v0 | v1 | v2 |
+ * v3 | V4 | v5 |
+ * \| | |/ |
+ * C3-H4-H5-C4-H6-H7-C5 |
+ * /| | |\ |
+ * v6 | v7 | v8 |
+ * v9 | v10 | v11 |
+ * \| | |/ |
+ * C6-------C7-------C8 |
+ * \ / \ / |
+ * H8 H9 H10 H11 |
+ * |
+ * When trying to get a patch at a certain position it justs builds it with the corresponding |
+ * points. |
+ * When adding a patch it tries to add the points at their corresponding position trying to comply |
+ * with the adjacent points or overwriting them. |
+ * |
+ * Based the idea on the SVG2 spec: |
+ * <meshGradient x="100" y="100"> |
+ * <meshRow> |
+ * <meshPatch> |
+ * <stop .../> |
+ * Up to four stops in first patch. See details below. |
+ * </meshPatch> |
+ * <meshPatch> |
+ * Any number of meshPatches in row. |
+ * </meshPatch> |
+ * </meshRow> |
+ * <meshRow> |
+ * Any number of meshRows, each with the same number of meshPatches as in the first row. |
+ * </meshRow> |
+ </meshGradient> |
+ */ |
+class SkMeshGradient { |
+ |
+public: |
+ SkMeshGradient(int rows, int cols); |
+ SkMeshGradient(int rows, int cols, const SkPoint* corners, const SkPoint* hrzCtrlPts, |
+ const SkPoint* vrtCtrlPts, const SkColor* colors); |
+ |
+ ~SkMeshGradient(); |
+ |
+ /** |
+ * Add a patch at location (x,y). The function returns false if none of the new patch's control |
+ * points are set, which may be because (x,y) are out of range or because the patch already |
+ * exists at the given location and overwrite was set to false. |
egdaniel
2014/08/07 17:58:55
what is overwrite here?
dandov
2014/08/07 18:11:46
Forgot to fix some of the comments. Overwrite was
|
+ * If overwrite is true then the patch is always set and overwrites the values of adjacent |
+ * patches. If it is set to false and the location is empty the function just set the control |
+ * that are "empty" meaning that it does not overwrite values of adjacent patches. |
+ */ |
+ bool addPatch(int x, int y, const SkPatch& patch); |
+ bool addPatch(int x, int y, const SkPoint ctrlPts[12], const SkColor colors[4]); |
+ |
+ /** |
+ * Get patch at location (x,y). If the patch is not NULL it sets patch's |
+ * control points and colors to the corresponding values. |
+ */ |
+ void getPatchAt(int x, int y, SkPatch* patch) const; |
+ |
+ /** |
+ * Resizes the mesh gradient to contain the given rows and cols of patches. |
+ * The function copies the values of the previous patches that are still within the new ranges. |
+ */ |
+ void resize(int rows, int cols); |
egdaniel
2014/08/07 17:58:55
Do you have a plan to use this function? My gut in
dandov
2014/08/07 18:11:46
I was thinking for a similar case as Illustrator's
|
+ |
+ /** |
+ * Resets the mesh gradient to contain rows and cols of patches. The main difference between |
+ * this and resize is that resize keeps the previous values of control points and colors and |
+ * this doesn't. |
+ */ |
+ void reset(int rows, int cols, const SkPoint* corners, const SkPoint* hrzCtrlPts, |
+ const SkPoint* vrtCtrlPts, const SkColor* colors); |
+ |
+ /** |
+ * Draws the mesh gradient. |
+ */ |
+ void draw(SkCanvas* canvas, SkPaint& paint); |
+ |
+ /** |
+ * Get the dimensions of the grid of patches. |
+ */ |
+ SkISize getDimensions() const { |
+ return SkISize::Make(fCols, fRows); |
+ } |
+ |
+private: |
+ int fRows, fCols; |
+ SkPoint* fCornerPts; |
+ SkColor* fCornerColors; |
+ SkPoint* fHrzCtrlPts; |
+ SkPoint* fVrtCtrlPts; |
+}; |
+ |
+ |
+#endif |